Means for automatically regulating the draft in locomotive boilers



I W. J. McCARROLL.

V MEANS FOR AUTOMATICALLY REGULATING THE DRAFT IN LOCOMOTIVE BOILERS- APPLICATION FILED MAR- 10, 192i.

1,437,766. Patented Dec. 5, 1922.-

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. J. McCARROLL.

MEANS FOR AUTOMATICALLY REGULATING THE DRAFT IN LOCOMOTIVE BOILERS.

APPLICATION FILED MAR. 10, I92].

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MEANS FOR AUTOMATICALLY nneonarrne Tran nnarr IN LOGOMO'IIVE BoILnns.

Application filed 'MarchlO, 1921. Serial no. 451,227.

To all whom it may concern Be it known that 1, WILLIAM J. McCAR- ROLL a citizen of the United States, residing at Melrose Park, in the county of Montgomery and State of Pennsylvania, have invented certain new and useful Improvements in Means for Automatically Regulating the Draft in Locomotive Boilers, of which the following is a specification. a

My invention relates to means for automatically regulating the draft in locomotive boilers, and more specifically considered, it relates to improved means forbreaking or reducing the vacuum in the smoke boxof the locomotive at certain times, for the purpose of effecting certain economies in the operation of the locomotive, as well as to minimize the frequency of blowing oif of the safety valve of the locomotive boiler; The principal object of my invention is to provide means for automatically breaking ori'educing the vacuum in the smoke box.

of the locomotive to thereby check the draft under certain conditions, and to thereby reduce the tendency of the boiler to blow off as frequently as now occurs. When a locomotive is standing, preparatory to the beginning of a run, it is desirable that the boiler pressure be maintained at a point near the blow-elf pressure, that is, near the pressure at which the safety valve is set, and it is also necessary under such conditions to keep the fire in an eflicient condition ready for quick steaming, which is required when the locomotive is started. on its run. The requirement to keep the locomotive under these conditions while standing in the station preparatory to a run, frequently results in the pressure at which the safety valve is set being exceeded, whereupon the safety valve will blow ed and considerable steam will be lost, together with the consequent loss of energy.

My present invention contemplates the provision of'a device which willaiitomatically break the vacuum in thesmoke boX of the locomotive in an efficient manner when the boiler pressure approaches that at which the safety or blow-off valve is set,

inconnection with the accompanying draw ings forming part hereof, in which Figure 1 is a longitudinal central section of the front end of the locomotive provided with a device embodying the main features of my present invention:

Fig. 2 is a transverse sectional view thereof taken approximately on theline 22 of Fig. 1;

Fig. 8 is a detail sectionalview, enlarged, illustrating a type of automatic valve adaptable for use ineonnection with the device shown in Fig. l; and I a Fig. i is a horizontal plan view, enlarged, taken approximately on the line l4; of F 2. I

Referring to the drawings,the particular embodiment of my invention therein shown is illustrated in connection with the front,

end of a locomotive of an ordinary type, but it should be understood that the general structural details of the locomotiveform no essential part of the present invention, but that the same is applicable to various types of locomotives at present in common use. 7 As shown in the drawings, 5 is the smoke box of the locomotivein which the exhaust nozzleG is mounted in the bottom portion thereof beneath the stack 7 the arrangement being such that the exhaust steam is projected upwardly from the exhaustnozzle 6 through the stack 7 to thereby create a partial vacuum in the smoke box 5, in the man ner well known to those skilled inthe art, the effect of such vacuum being to create J. the necessary draft through the boiler tubes 8 to maintain the fire in the proper condition under the various conditions of operation of the locomotiv I 7 Around the base of the exhaust nozzle 6 there is mounted a steam pipe 9 in the form of a ring having a plurality of outlet orifices 10 to permit jets of live steam to escape from the ring shaped pipe 9 aroundthe base of the exhaust nozzle. 1 The ring shaped pipe 9 is connected by means of a pipe line 11 to an automatic valve 12, which in turn is connected to the top of the boiler so as to per-" point, which point will preferably be a few pounds less than the pressure at which the main safety valve of the boiler is set to blow off. A. type of valve suitable for this purpose is illustrated in Fig. 3 of the drawings, which, as there shown, con'iprises a housing); 13, in which is mounted a valve disc 14, normally closing the passageway 15 extending from the boiler. The valve is normally held on its seat by means of a spring 16, the ten sion of which may be adjusted by advancing or retrustingthe plug 1? which is threacled in the upper portion of the housing 13. The upper end of the housing is closed by means of a suitable cap member 18, which also serves as a guide for the upper end of the valve stem 19. It should, of course, be understood that the particular construction of this valve forms no essential part of the invention, but that any type of valve may be employed which will accomplish the purpose hereinbefore mentioned, namely, permitting the steam to pass from the top of the boiler to the pipe line 11 when the pressure in the boiler exceeds a pre-determined limit.

The operation of the device may now be readily understood. lVhen the locomotive is standing idle, for example, in the station preparatory to a run, the lire is usually maintained in a good condition for rapid steaming, with the consequent result that many times the pressure at which the main safety valve is set will be exceeded and the boiler will blow off, with the consequent loss resulting therefrom. With the device of my present invention, the automatic valve 12 will come into operation when the boiler pressure approaches the limit fixed by the main safety valve, and will permit live steam to pass from the top of the boiler through the pipe line 11 to the ring shaped pipe 9, and to thence escape through the outlet orifices 10, whereby the live steam will expand in considerable volume around the base of the exhaust nozzle in the bottom of the smoke box 5, and thus effectually and effectively break the vacuum in said smoke box, and thereby reduce the draft through the fines 8. In this manner, the burning of the fire in the furnace will be retarded, and thus the tendency of the same to cause a further increase in pressure of the steam in the boiler will be reduced.

It will be seen that there is thus provided a simple and eflicient device requiring little or no attention when once properly adjusted, which will automatically control the draft in the boiler, whereby the fire may be maintained in an eflicient condition ready for rapid steaming without causing frequent blowing off at the main safety valve, such as now usually occurs under the conditions above mentioned.

Having thus described the nature and characteristic features of my invention,

what I claim as new and desire to secure by Letters Patent, is:

l. The combination in a locomotive having a boiler provided with a smoke box at the end thereof, a stack communicating therewith and an exhaust nozzle under the stack, of a device adapted to discharge steam in said smoke box and means for antomatically supplying live steam from the boiler to the discharging device when the pressure in the boiler exceeds a predetermined limit. d

2. The combination in a locomotive having a boiler provided with a smoke box at the end thereof, a stack communicating therewith and an exhaust nozzle under the stack, of a device adapted to discharge steam in the base of said smoke box, a pipe line extending therefrom and communicating with the top of the boiler, and automatic means for permitting live steam to pass from the boiler through said pipe line when the pressure in the boiler exceeds a predetermined limit.

3. The combination in a locomotive having a boiler provided with a smoke box at the end thereof, a stack communicating therewith and an exhaust nozzle under, the stack, of a device adapted to discharge steam in the base of said smoke box, a pipe line extending therefrom and communicating with the top of the boiler, and an automatic valve interposed in said pipe line adapted to permit live steam to pass from the boiler through said pipe line when the pressure in the boiler exceeds a predetermined limit.

4. The combination in a locomotive hav ing a boiler provided with a smoke box at the end thereof, a stack communicating therewith and an exhaust nozzle under the stack, of a device adapted to discharge steam in the base of said smoke box around said exhaust nozzle, a pipe line extending therefrom and communicating with the top of the boiler, and an automatic valve interposed in said pipe line adapted to permit live steam to pass from the boiler through said pipe line when the pressure in the boiler exceeds a predetermined limit.

5. The combination in a locomotive having a boiler provided with a smoke box at the end thereof, a stack communicating therewith and an exhaust nozzle under the stack, of a device having aplurality of out let orifices adapted to discharge steam in the base of said smoke box, a pipe line extending therefrom and communicating with the top of the boiler, and an automatic valve interposed in said pipeline adapted to permit live steam to pass from the boiler through said pipe line when the pressure in the boiler exceeds a predetermined limit.

6. The combination in a locomotive having a boiler provided with a smoke box at the end thereof, a stack communicating therewith and an exhaust nozzle underthe stack, of a device having a plurality of outlet orifices adapted to discharge steam in the base of said smoke box around said exhaust nozzle, a pipe line extending therefrom and communicating with the top of the boiler, and an automatic valve interposed in said pipe line adapted to permit live steam to pass from the boiler through said pipe line when the pressure in the boiler exceeds a predetermined limit.

7. The combination in a locomotive having a boiler provided with a smoke box at the end thereof, a stack communicating therewith and an exhaust nozzle under the stack, of a pipe arranged adjacent said exhaust nozzle at the lower portion of the smoke box and having a plurality of outlet orifices adapted to discharge steam in the base of said smoke box, a pipe line extending therefrom and communicating with the top of the boiler, and an automatic valve interposed in said pipe line adapted to permit live steam to pass from the boiler through said pipe line when the pressure in the boiler exceeds a predetermined limit.

8. The combination in a locomotive having a boiler provided wlth a smoke box at the end thereof, a stack communicating therewith and an exhaust nozzle under the stack, of a pipe at the lower portion of the live steam to pass from the boiler through said pipe line when the pressure in the boiler exceeds a predetermined limit.

9. The combination in a locomotive having a boiler provided with a smoke box at the end thereof, a stack communicating therewith and an exhaust nozzle under the stack, of a ring shaped pipe surrounding said exhaust nozzle at the lower portion of the smoke 'box and having a plurality of outlet orifices adapted to discharge steam in the base of said smoke box around said exhaust nozzle, a pipe line extending therefrom and communicating with the top of the boiler, and an automatic valve interposed in said pipe line adapted to permit live steam to pass from the boiler through said pipe line when the pressure in the boiler exceeds a predetermined limit.

In testimony whereof, I have hereunto signed my name.

WILLIAM J. MQCARROLL. 

